by SAVIOUS KWINIKA
JOHANNESBURG, (CAJ News) – IQAir has released its 8th annual World Air Quality Report, providing a comprehensive analysis of global air pollution in 2025 and highlighting persistent health risks, shifting regional trends, and critical gaps in air quality monitoring.
The report draws on data from monitoring stations in 9,446 cities across 143 countries, regions, and territories.
It includes 12 additional countries and territories compared to last year, with seven appearing in the dataset for the first time, reflecting the continued expansion of global monitoring coverage.
Despite this progress, air quality remains a major concern. Only 14% of cities worldwide met the World Health Organization (WHO) annual PM2.5 guideline of 5 µg/m³, down from 17% in 2024.
Just 13 countries and territories achieved compliance: French Polynesia, Puerto Rico, the U.S. Virgin Islands, Barbados, New Caledonia, Iceland, Bermuda, Réunion, Andorra, Australia, Grenada, Panama, and Estonia.
Overall, 91% of assessed regions exceeded the WHO guideline.
The world’s most polluted countries in 2025 were Pakistan, Bangladesh, Tajikistan, Chad, and the Democratic Republic of the Congo (DRC).
Loni, India, ranked as the most polluted city, with an annual PM2.5 concentration of 112.5 µg/m³—more than 22 times the WHO guideline and a 23% increase from the previous year.
In contrast, Nieuwoudtville, South Africa, recorded the cleanest air globally at 1.0 µg/m³.
The 25 most polluted cities were all located in India, Pakistan, and China, with India accounting for three of the top four.
In the United States, El Paso, Texas, was the most polluted major city, while the Southeast Los Angeles region ranked as the most polluted area overall.
Seattle, Washington, remained the cleanest major U.S. city for the second consecutive year.
Regionally, trends varied. East Asia recorded a second consecutive year in which no cities met WHO PM2.5 standards, with pollution in China showing a westward shift.
Europe experienced mixed results, with 23 countries reporting increased pollution and 18 showing improvements.
Seasonal factors—including winter wood burning, wildfire smoke from Canada, and Saharan dust—contributed to elevated pollution levels.
Latin America and the Caribbean showed overall improvement, with 208 cities reporting lower pollution levels.
Oceania remained one of the cleanest regions globally, with 61% of cities meeting WHO guidelines, although extreme cold in New South Wales, Australia, caused temporary pollution spikes.
Wildfires, intensified by climate change, were a major driver of global air pollution in 2025. Record emissions from fires in Europe and Canada released an estimated 1,380 megatons of carbon.
Canada experienced its second-worst wildfire season on record, contributing to higher pollution levels across North America and parts of Europe.
In the United States, average PM2.5 levels rose slightly to 7.3 µg/m³ from 7.1 µg/m³ in 2024, largely due to wildfire smoke.
El Paso saw a 46% increase in pollution driven by severe dust storms—the highest number recorded since the 1930s.
Monitoring capacity also declined in some regions. The closure of the U.S. State Department’s air quality monitoring programme at embassies and consulates in March 2025 reduced access to reliable data for millions.
According to the Centre for Research on Energy and Clean Air (CREA), monitoring efforts weakened in 44 countries, with six losing access entirely.
“Air quality is a fragile asset that requires active stewardship to protect public health,” said IQAir Global CEO Frank Hammes.
“Without robust monitoring, we cannot fully understand the air we breathe. Expanding access to real-time data empowers communities to act.”
Dr Aidan Farrow, Senior Scientist at Greenpeace International, added that the report highlights both the scale of the pollution crisis and the growing role of data-driven accountability.
“Open and transparent data is essential for holding polluters accountable and securing a healthy environment for all,” he said.
The report underscores the urgent need to expand air quality monitoring networks, particularly through affordable sensor technologies that enable communities, researchers, and policymakers to respond effectively.
IQAir’s 2025 World Air Quality Report serves as a critical global benchmark for understanding pollution exposure, informing policy decisions, and accelerating efforts to improve air quality worldwide.
IQAir is a Swiss technology company that empowers individuals, organisations, and governments to improve air quality through data, collaboration, and targeted interventions.
– CAJ News